To summarize what I've personally gleaned from reading, looking at reports, videos, some analysis done here some time back etc.
The conclusions are mine, and I could be wrong.
More weight on the nose makes a flip more likely. Vans themselves published a maximum nose weight specification a few years ago.
More weight from: bigger engine, metal and/or CS prop. All of this puts more weight up front. I'm guessing just more weight in general will load the nose leg more when in a bad situation.
The 7A *may* be a bit more likely to have an issue. The 7A typically is heavier, and the main gear is taller. Way back when there was a thread that tried to look at stats, but frankly the number of incidents is so small that there isn't statistical confidence.
The usual axle design of the 6A nose wheel *may* make the 6A more vulnerable. [There are multiple designs out there, early / late from the factory, Anti-Splat, other 3rd parties, and the factory design on the 7A] The axle may be under tightened and the tapered roller bearings *may* bind on a hard landing. Some years ago there was a video of an RV-10 that had the nose wheel lock on landing. Anti-Splat makes a ball bearing conversion, and Van's offers a newer nose wheel axle design - both of which should eliminate this risk.
Operating this tiny nose wheel on any rough field has risks. Think gopher holes, pot holes...
All that said, my 6A insurance is cheaper than if my plane had a tailwheel. So the risk probably is less than ground looping?
Let me repeat, these are my opinions. But I think some of these could have a grain of truth.
I won't get into landing technique as I expect that will be extensively posted by others here
Oh, lastly, it wouldn't be impossible to convert it to a tailwheel. Easy, not so much, but not impossible.